Gastrointestinal Tract Flashcards
What does the GIT contain?
Oral cavity
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
What is the oral cavity supported by?
The jaws
Where do the teeth lie?
In sockets on the jaws
Where does the tongue lie?
On the floor of the oral cavity, held by frenulum
What is the oral cavity separated from the nasal cavity by?
The palate → anteriorly hard, posteriorly soft
What is pharynx?
Muscular tube that is posterior to the nasal cavity above and oral cavity below, transmitting air and food respectively
What is the pharynx divided into?
Nasopharynx → at the back of the nose
Oropharynx → at the back of the oral cavity
The oropharynx continues downwards as what?
The esophagus
What are the contents of the pharynx?
Epiglottis
Tonsils → 2 of them, 1 at each side of the oropharynx
What is esophagus
A long straight muscular tube connecting the pharynx superiorly with the stomach inferiorly
The lower end of the esophagus is kept closed by what?
By the lower esophageal sphincter, which is a muscular narrowing at the junction between the esophagus and stomach
What is stomach?
A hollow, J-shaped muscular bag lying under the diaphragm
It follows the esophagus and continues as the duodenum distally
What are the parts of the stomach?
Fundus
Body
Pylorus
Lesser curvature
Greater curvature
What is the blood supply of stomach?
Supplied by the celiac trunk, a branch of the descending abdominal aorta
What is the anterior relations of stomach?
Left lobe of the liver
Diaphragm
Anterior abdominal wall
What is the posterior relations of stomach?
Pancreas
Spleen and the splenic artery
What is the small intestine?
A hollow muscular tube that is 6 meters long
It’s coiled up forming loops that fill in the abdominal cavity
What are the parts of small intestine?
Duodenum
Jejunum
Ileum
Describe duodenum
C-shaped
Shortest part
Connected to stomach above and jejunum below
Receives the opening of bile and pancreatic ducts
Bile and pancreatic juices mix with food
Describe jejunum
Between the duodenum and ileum
a lot of villi
For absorption
Describe ileum
Between the jejunum and large intestine
Opens into cecum of the large intestine by the ileocecal valve
For absorption
What does large intestine do?
Extends from the end of the ileum to anus
What are the parts of the large intestine?
Cecum
Colon
Rectum
Anal canal
What is cecum?
Bag-like
ileum opens into it by the ileocecal valve
Appendix
What does the colon divide into?
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
What is the ascending colon
Extends from the cecum to the lower border of the liver where it takes a bend forming the right colic flexure
What is the transverse colon?
Lies horizontally below the liver and stomach.it covers the upper coils of the small intestine. As it turns downwards it forms the left colic flexure
What is the descending colon?
Continues downwards
What is the sigmoid colon?
S-shaped, lies in the pelvis
What is rectum?
Lies in front of the sacrum
What is anal canal?
Ends at the anus that is guarded by the internal and external anal sphincters
What does the abdominal aorta gives?
The superior mesenteric artery and the inferior mesenteric artery
What does the superior mesenteric artery supplies?
Small intestine
Right-sided parts of the large intestine → cecum, appendix, ascending colon right half of the transverse colon
What does the inferior mesenteric artery supplies?
The rest of the large intestine → left half of the transverse colon, descending colon, sigmoid colon and rectum
